This invention relates to a heating device, particularly to a preheater for heating air which in turn is to be mixed with the fuel-air mixture for the ease of combustion in a cold weather.
It is known in the art to preheat the air before entering into the engine so that a warm fuel-air mixture can be rendered for ease of combustion. In one form of the preheater, the air is preheated by the heat of the exhaust. In another form of the preheter, the air is heated by the heat of the engine body. However, it is found that both are deficient since they can only heat the air after the engine operates. If the engine is required to start in a very cold weather, the above preheaters are of no use.